Sarcher is right, it's system dependent.
I would just try all the available settings. I found that for my cart, the midrange popped into focus at a certain setting, and it was quite a bit higher than the value everyone else was using.
If you have to supply your own resistors, I'd try maybe 3 resistor values, like 1000, 500, 100 Ohms.
MC carts *shouldn't* be sensitive to capacitance, but you might want to try different capacitive loading anyway, or tonearm cables with lower capacitance.
I would just try all the available settings. I found that for my cart, the midrange popped into focus at a certain setting, and it was quite a bit higher than the value everyone else was using.
If you have to supply your own resistors, I'd try maybe 3 resistor values, like 1000, 500, 100 Ohms.
MC carts *shouldn't* be sensitive to capacitance, but you might want to try different capacitive loading anyway, or tonearm cables with lower capacitance.